Neke fizičko-hemijske karakteristike maslinovog ulja iz Libije

Olives in Libya are a basic agricultural commodity. Moreover, olive oil is mostly produced by local producers using a cold-pressing process. To the best of our knowledge, there is no literature data on the quality of olive oils produced in Libya. Therefore, the scope of this research was to analyze the most important parameters for olive oil identification that originated in Libya. Analyses of the oil produced in 5 different geographical regions in Libya, produced by differ- ent oil manufacturers, have shown that the oils are not significantly different and are meeting legislated parameters for olive oil quality. It was determined that the iodine value (IV) of investigated oils was in the range of 80 to 87 g/100g, while the refractive index did not vary much, 1.464 to 1.469. Similarly, saponification value (SV) was rather close in values, 188.0-197.0 mgKOH/g, as well as the content of unsaponified matter, 7.7-9.0 g/kg. The oil sample from the Zwit region had the lowest relative density, 0.910 (20oC/water 20oC), while the oil from the El Farok region had the highest value for density, 0.915.Osnovna uljana kultura u Libiji je maslina, pri čemu ulje proizvode uglavnom individualni proizvođači postupkom hladnog presovanja. Po našim saznanjim u literaturi uopšte nema podataka o kvalitetu maslinovog ulja proizvedenog u Libiji. S toga, u ovom radu su analizirani najvažniji pokazatelji za identifikaciju maslinovog ulja poreklom iz ove zemlje. Analiza osnovnih parametara fizičko-hemijskog kvaliteta pokazala je da se ulja proizvedena u 5 različitih regija - geografskih područja Libije od strane različitih proizvođača međusobno ne razlikuju bitno jedna od drugih, i da ispunjavaju zakonom predviđene okvire. Utvrđeno je da jodni broja ispitivanih ulja ima vrednosti od 80 do 87 g/100g, dok indeks refrakcije varira u uskom intervalu, od 1,464 do 1,469. U rezultatima saponifikacionog broja i sadržaju neosapunjivih materija nije bilo velikih odstupanja između analiziranih ulja, budući da su im vrednosti iznosile, respektivno, 188-197 mgKOH/g i 7,7-9,0 g/kg. Uzorak ulja iz regije Zwit imao je najmanju zapreminsku masu, 0.910, dok je ulje iz regije El Farok imalo najveću vrednost zapreminske mase, 0.915

Characteristics of blackberry and raspberry seeds and oils

This study is concerned with the determination of technological quality characteristics of dried pomaces, i.e. blackberry and raspberry seeds, along with the quality parameters, content of total carotenoids and chlorophyl and transparency of crude extracted oil (using organic solvent). Blackberry seeds (Rubus fruticosus L.) were obtained from a domestic variety Čačanska bestrna, while the raspberry seeds (Rubus idaeus L.) were of the variety Willamette. Oil content of the blackberry pomace was 13.97 and 14.34%, while the oil content of the raspberry pomace was 13.44 and 14.33% on dry basis (d.b.). In regard to technological characteristics of the pomaces, i.e. volumetric and specific weight, no considerably difference was found. However, a weight test for 1000 seeds showed a significant difference in weight: 3.5 g (d.b.) for the blackberry pomace and 1.5 g for the raspberry pomace (d.b.). Proximate analysis of blackberry seed oil showed that this oil had better quality since the FFA value was 3.43% (sample B1) and 3.53% (sample B2), while the peroxide value was 8.89 and 11.16 mmol/kg, respectively. Raspberry seed oil had higher FFA (8.59 and 8.83% for sample R1 and R2) and peroxide values (13.99 and 13.84 for sample R1 and R2) than the blackberry seed oil. Crude extracted blackberry seed oil had a brown-greenish color due to the high total chlorophyll content (around 3000 mg/kg dissolved in cyclohexane). Raspberry seed oil had a dark yellowishorange color, due to lower chlorophyll content (around 200 mg/kg) compared to the blackberry seed oil, while the content of total carotenoids was slightly higher in this oil (around 40 mg/kg) compared to the blackberry seed oil (33 mg/kg). [Projekat Ministarstva nauke Republike Srbije, br. TR 31014: Development of the new functional confectionery products based on oil crops

Chemical characterization of hull-less pumpkin seed oil press-cake

The utilization of agricultural waste products to produce food has recently received increased attention, not only to minimize waste disposal problems, but to help maximize potential resources and production of new and novel food products. The objective of this study was to characterize the pumpkin oil press-cake, a by-product of the pumpkin seed oil pressing process. The cakes were obtained by pressing the domestic variety of hull-less pumpkin seeds (Cucurbita pepo L.) "Olinka". Two pressing processes were applied: using a continual screw press in cold-pressed oil manufacturing and hydraulic press in the virgin pumpkin oil pressing process. In order to assess the suitability of this by-product, proximate analyses of the samples were conducted to determine the residual oil and water contents, as well as proteins, carbohydrates, crude fibers and ash using official methods of analysis. The residual oil was also analyzed in order to determine its nutritive quality. The obtained results showed that two kinds of oil press-cakes were significantly different in terms of oil and water contents. The press-cake obtained using a screw press had higher water content (8.30 ± 0.40%) and lower residual oil content (13.41 ± 1.48%), compared to the press-cake obtained using a hydraulic press (3.94 ± 0.65% water content and 18.18 ± 9.44% residual oil). In addition, the pumpkin press-cakes had a substantial amount of high quality proteins. The protein content of the press-cake obtained using a screw press was 67.09 ± 3.08 % d.m., while the protein content in the cake obtained using a hydraulic press was 59.20 ± 5.13% d.m. Results have also confirmed that the residual oil, regardless of the pressing method used, was of high quality, especially in terms of the high content of the essential omega-6 (linoleic fatty acid) and gamma tocopherols. The obtained results confirmed that both press-cakes can be used in different applications as value-added, functional ingredients for food manufacture

Impact of the seed storage time on the quality of cold-pressed sunflower oil

The objective of this study was to investigate the impact of seed storage time on the quality of cold-pressed sunflower oil. The quality and oxidative stability of oil was determined in samples of domestic varieties of sunflower hybrid, linoleic type seeds, obtained from fresh seeds and from seeds stored in silo cell for 6 and 12 months at temperature below 30oC and in good ventilation conditions. It was found that the longer storage time of seeds had a negative impact on many quality aspects of the oil, such as flavor, odor and aroma, primarily on the sensory profile. Chemical characteristics and oxidative stability of oil were also influenced by the storage time, which was confirmed by increased values of the acid value (AV) and peroxide value (PV) of the oil samples. Fresh seed oil had an AV of 0.49±0.01 mgKOH/g, while oils that were obtained from one-year old seeds had an AV of 1.95±0.02 mgKOH/g. Content of the primary oxidation products in the oil obtained by cold-pressing of the fresh seeds was 1.73±0.02 mmol/kg (measured as PV), and 2.22±0.07 mmol/kg in that from the seeds stored for 12 months. The anisidine value for the oil obtained from the seeds stored for 12 months was 0.86±0.04 (100A1% 350nm).[ Projekat Ministarstva nauke Republike Srbije, br. TR 31014